Karyotype alterations of BHK-21 cell lines by persistent virus infections I. Development of the cell lines and conventional chromosome analysis.

From BHK-21 cell cultures inoculated with different viruses cell lines with persistent infection were developed and examined for alterations in their karyotypes. In all cell lines studied, even in those no longer producing infective virus chromosomal breaks and interchanges were observed. Besides these effects probably induced directly by the virus infection, a shift in the number of chromosomes was found. Based on certain properties of the BHK-21 cell lines carrying a virus infection a hypothesis is discussed concerning the cooperation of various cellular and viral factors which enable a virus to persist.